混沌同步系统降噪方法及其在滚动轴承故障诊断中的应用

提出了一种基于混沌同步系统的降噪方法，将其应用于滚动轴承振动信号的前期处理，并结合功率谱密度进行故障诊断.分析Chua电路混沌同步系统的降噪机理，讨论系统处于不同运行状态时，输入信号对相空间运行轨迹的影响；搭建混沌同步系统降噪模型，分析其检测特性，并与其他方法进行比较；将滚动轴承不同损伤模式下测得的振动信号输入该模型，比较振动信号和同步误差信号的时域波形和功率谱密度，并通过峰值查找，匹配对应的故障特征频率.新方法利用了混沌系统的噪声免疫性和可同步性，避免了现有方法参数设定复杂和运行状态判定困难的问题.结果表明该方法可有效提升被测信号的信噪比，能与传统方法结合形成新的故障诊断方法. 

Noise Reduction Method Based on Chaotic Synchronization System and Its Application in Fault Diagnosis of Rolling Bearing

A noise reduction method was proposed based on the chaotic synchronization system, and was applied to process the vibration signal of the rolling bearing and to diagnose the bearing fault in combination with the power spectral density. Firstly, analyzing the noise reduction mechanism of the chaotic synchronization system, the influence of the input signal on the phase space trajectory was discussed for different running state. Then, a noise reduction model of the chaotic synchronization system was built based on the Chua''s circuit, analyzing its characteristics and comparing with other methods. Finally, taking the actual vibration signals of three different damage modes of rolling bearing as the input of the model, the waveform and the change of power spectrum density of vibration signal and synchronous error signal were compared based on their respective fault characteristic frequencies. Taking advantages of the noise immunity and synchronism of the chaotic system, the problems of parameter setting complexity and the decision difficulty of the system running state can be avoided in the existing chaotic detection methods.The experimental results show that the new chaotic synchronization system can effectively improve the signal to noise ratio of the measured signal, and is suitable for the pre-processing of the signal. And it can be combined with the traditional method to form a new fault diagnosis method.